
#include <cstdarg>
struct TreeNode {
  int val;
  TreeNode *left;
  TreeNode *right;
  TreeNode()
      : val(0), left(nullptr), right(nullptr){} * TreeNode(int x)
      : val(x),
        left(nullptr),
        right(nullptr){} * TreeNode(int x, TreeNode *left, TreeNode *right)
      : val(x),
        left(left), right(right) {}
};

TreeNode *searchBST(TreeNode *root, int val) {
  if (!root)
    return nullptr;
  if (root->val == val) {
    return root;
  } else if (root->val < val) {
    return searchBST(root->right, val);
  } else {
    return searchBST(root->left, val);
  }
}